We are continuing to study the effects serum and serum components on various parasitic helminths to determine which immune mechanisms are deleterious or protective, mode of action of antibodies, methods of practical value in immunization, vaccination, and diagnosis, and immune phenomenon in parasitic infections in which the host damages itself, e.g. hypersensitivity reactions and other immunologic disease states. We are continuing work on the possible relationship of anti-DNA antibodies in parasite infections and production of immune complex damage to the kidney of such animals. To date our positive findings on anti-DNA complexes have been limited to various schistosome species and the nematode infections Trichinella spiralis and Nippostrongylus muris have not indicated this immunologic reaction. Since among the schistosomes, the rodent-adapted Formosan strain of the parasite also does not produce anti-DNA nor does it have the extensive kidney pathology seen in other schistosome strains, studies are continuing on Schistosomatium douthitti, a rodent-adapted parasite to determine whether it produces pathology and anti-DNA. Since DNA antibody complexes are implicated in the kidney pathology attempts are being made to determine whether parasite and/or host DNA enter into this phenomenon.